Some statements about Leclanché cell are:
$(I)$ Anode is zinc metal
$(II)$ Cathode is graphite rod surrounded by powdered $MnO_2$ and carbon
$(III)$ Electrolyte is a moist paste of $ZnO$ and $KOH$
$(IV)$ Oxidation product is $ZnO$
The correct statements are:

$A$ button cell used in watches functions as follows:
$Zn_{(s)} + Ag_2O_{(s)} + H_2O_{(l)} \rightarrow 2Ag_{(s)} + Zn^{2+}_{(aq)} + 2OH^{-}_{(aq)}$
If the half-cell potentials are:
$Zn^{2+}_{(aq)} + 2e^- \rightarrow Zn_{(s)} \,;\, E^o = -0.76 \, V$
$Ag_2O_{(s)} + H_2O_{(l)} + 2e^- \rightarrow 2Ag_{(s)} + 2OH^{-}_{(aq)} \,;\, E^o = 0.34 \, V$
The cell potential will be $..........$ $V.$

The limiting molar conductivity $\Lambda^o$ for $NaCl$,$KBr$ and $KCl$ are $126$,$152$ and $150 \ S \ cm^2 \ mol^{-1}$ respectively. The $\Lambda^o$ for $NaBr$ is (in $S \ cm^2 \ mol^{-1}$).

Which statement is correct for a fuel cell?

Which of the following solutions cannot be used in a salt bridge?

For a general redox reaction:
Anode: $Red_1 \to Ox_1^{n_1+} + n_1 e^-$
Cathode: $Ox_2^{n_2+} + n_2 e^- \to Red_2$
Which of the following statements is incorrect?